Adoption is the percentage of production deployments running the project based on the latest biannual user survey results.
Maturity comes from looking at 5 distinct tags that indicate stability and sustainability. The current criteria includes whether or not the project has an install guide, whether it is supported by 7 or more SDKs, if the adoption percentage is greater than 75%, whether or not the team has achieved corporate diversity and whether or not there are stable branches.
Age is the number of years the project has been in development.